Felted water-resistant sheet fiberboard



Nov. 2l, 1944. H. w. RICHTER 2,363,439

FELTEDWATER"RESISTANT SHEET FIB-ERBOARD Filed July' 25, 1940 leatherboard heel resistant. Although attempts have been made to produce felted water-resistant sheet fiber board heel bases containing asphalt,

the product should of a bituminous pitch Patented Noam, 1944 FELTED WATER-RESSTAN T SHEET i FIBERBOARD Herman W. Richter, Bridgewater,

to George 0. Jenkins Company,

Mass., assignor Bridgewater,

Mass., a corporation of Massachusetts Application July 25, 1940, serial' No. 341,468 4 claims. (ci. 10s-156) This invention relatesto a novel felted waterresistant sheet fiber board useful inthe manufacture of heel bases and heels for boots and shoes and isa continuation in part of my application for United States Letters Patent Serial No. 225,955, led August 20, 1938.

So far as I am aware, prior to principally from leather, leatherboard or rubber. Since the principal use to which the product is intended to be put is for heel bases, I shall refer primarily to that use, intending, however, to include reference to heels as well as heel bases wherever the words heel base are used. Rubber heel bases are expensive and are somewhat unsatisfactory in the finishing operation; leather heel bases are expensive and are not water resistant; and bases likewise are not .water they have not met with success because the waterproofing material has hardened the heel base material to such' an extent that the trimming knives are very rapidly dulled, making its use uneconomical and, furthermore, the waterproofing material has loaded the sandpaper in the scouring operation so rapidly that the use of suchheel base material is uneconomical for this additional reason.

I have discovered that a felted sheet product containing at least 50% by weight of fiber (including leather fiber and paper or o and from 8% to 20% inclusive of a bituminous pitch-type waterproofing agent, such as asphalt, provides a water-resistant product which is of great utility in the manufacture of heel bases and which is also relatively inexpensive as compared to leather or rubber.. I have-also discovered that also containrat least '9% of leather fiber and enough fiber other than leather to-make a total fiber content of at least 50% by weight.

The principal object of this invention is to provide a felted Water-resistant sheet fiber board useful in the manufacture of heel bases and heels.

Further objects are to provide such Va fiber 'board in which the waterproofing agent is of such this invention heels and heel bases have been made A further object is to provide such a ber board containing at least 9% by weight of leather fiber and other fiber in suflicient quantity to make a total fiber content of at least 50% by weight.

Other objects will be apparent from'the annexed specification and drawing.

In the drawing:

Fig. 1 is a plan view of a sheet of fiber board f made in accordance with this invention;

Fig. 2 is a perspective of a heel base after the l gouging Operation has been performed thereon;

Fig. 3 is a cross section on the line 3-3 of Fie. 2;

Fig. 4 is a perspective of a completed heel base after the compressing operation has been performed thereon;

ther fibers) a character and is incorporated in such a man.

ner that the heel bases may be trimmed without unduly dulling the trimming knives and scoured without unduly loading the sandpaper.

A further object is to provide such a ber board containing from 8% to 20% inclusive by weight -type base asl the waterproofing agent. l

' chine.

Fig. 5 is a cross section Fig. 4;` and Fig. 6 is a perspective of a heel made in accordance with this invention.

In the use of a sheet product for making vheel lifts a. plurality of heel lifts l!! are dinked or cut of a sheet Il or strip of the heel base material. which material may conveniently bev approxi-A mately 11.; of an inch in thickness. (Figs. 2 and 3) is then made in the upper flat surface of the heel lift, this operation being performed upon any standard heel lift gouging ma- The gouge slopes rearwardly and upfrom the breast.l3 of the heel base and also slopes outwardly and upwardly toward the curved edge I4 thereof. The gouged lift then goes to a heel compressor which compresses the gouged lift to form the final uniform heel seat or cup l5 of the heel base. This heel seat may be moulded or compressed to any suitable curvature to comply with the particular last to be used in making the shoe, to the end that the heel seat will snugly conform to the contour of the corresponding portion of the sole of the shoe. 'The material of which the heel base is made must on the lines 5-'-.5 of.

Wardly lend itself readily to the gouging and compress- I A fougeiZ heel base'and heel lift or lifts are oe,the heel seat engaging the sole of the The exposed surfaces of heel lifts y burnished or polished. The material of which the heel base is made must lend itself readily to these trimming, scouring and finishing operations.

A womans heel is shown in Fig. 6, the top lift I6 being made either of leather or of my novel heel base material and the other heel lifts and the base lift I1 being made of my novel heel base material.

This invention contemplates the use of afeitedsheet of brous materiall as the heel base material. The sheet material may be made on paper-making machines of various types from a furnish of beaten bers; for example, on a standard wet machine. The invention also contemplates the4 use of any bitumen pitch-type base as the Waterproong material. Examples of such suitable bases are asphalts, bituminous or hydrocarbon materials, tars, pitches of vege table, animal or mineral origin, and other similar materials. By the notation bituminous pitch-type base, Wherever used in this specication and in the annexed claims, I intend to include any of said materials. Of these bituminous pitch-type base materials I prefer to use asphalt and I will therefore describe the process with specific reference thereto, although it will be understood that any of the other materials may be substituted for the asphalt.

The asphalt base may be incorporated in the sheet product in any suitable manner, but I prefer to add it directly to the beater in the form of a-water emulsion or dispersion so that it is mixed with the ber stock in the beater and thereafter passed over a Wet machine, where it is formed into a felted sheet, which sheet is subsequently dried.

The water dispersion of asphalt or other base may conveniently be made as disclosed in United States Patent No. 1,615,303. For example, a mixture of colloidal' clay and water is made by agiasphalt is slowly added. the asphalt the mixture the asphalt becomes dispersed in fine particle form, the water comprising the external phase, the asphalt the internal or dispersed phase, the latter being insulated or protected by the clay.

After the fibrous material, which preferably includes leather and cellulosic bers and may include other bers, has been thoroughly beaten in a Hollander or other beater, a small quantity of sodium silicate solution' is added thereto and mixed therewith, and the asphalt dispersion is then added to the beater and thoroughly mixed with the stock. Aluminum sulfate is then added to the beater and this silicate to form a ilocculent precipitate which is probably aluminum silicate. This precipitate deposits the asphalt particles about the fibers of the stock and the resultant stock is then passed over the Wet machine and formed into sheets. The sheets are usually builtl up to a thickness of approximately '3A of an inch and are then dried in the usual manner. Other suitable iiccculati-ng agents 4vto deposit the asphalt particles upon the fibers ofv tation and to it molten During the addition of is rapidly agitated and the stock are disclosed in United States Patent No. 1,708,926. A suitable stock may be made as follows: 940 pounds of waste paper material and 250 pounds of leatherboard 'chips are placed in the beater and thoroughly beaten. The leatherboard comprises substantially 85% leather liber and paper fiber, so that such a stock would conreacts with the sodium` 'the felting operation,- so

tain about 977.5 pounds of paper ber and 212.5 pounds of leather fiber. 50 pounds of an aqueous sodium silicate solution is then added to the stock in the beater. This sodium silicate solution contains 38.7% of sodium silicate, so that approximately 19.35 pounds of sodium silicate and 30.65 pounds of Water are added in this step. 455 pounds of asphalt dispersion are then added to the stock in the beater. This dispersion contains approximately 52% asphalt, 8%

thereof remains in the dried product. Approxiof the silicate and alum is lost in that the dried product contains approximately 50% of the amounts originally added. Thus the dry product made from the aforesaid furnishv contains approximately 977.5 pounds of paper ber, 212.5 pounds of leather liber, 213 pounds of asphalt, 32.8 pounds of clay, and 28.4 pounds of aluminum silicate; that is, the dry product contains approximately 66.76% paper, 14.51% leather, 14.56% asphalt, 2.24% clay, and 1.93% aluminum silicate. i

It will be obvious to persons skilled in the art that; coloring pigments, such as carbon black, ochre, iron oxides, etc., may be added in small percentages to vary the color of the final product. -Some asphalts without the addition of any coloring agent produce a brown colored board.

It will also be apparent that llers such as powdered talc may also be added insome quantities to the aforesaid furnish. Talc, in addition to having the properties of a filler, isalso believed to have the property of improving the ply adhesion. In any event, I have found that the linal dry product must contain from 8% to 20% inclusive of asphalt, and Wherever I use the notation 8% to 20% in this specification or claims, I intend that it shall include 8% and 20% even though the Word inclusive is not used.

I have found that when the asphalt content exceeds 20%. by Weight of the dried product, there is appreciable' loading of the sandpaper in scouring, there is considerable di'iculty with the dulling of the trimming knives during the trimming operation, and the lifts adhere to the die in the dinking operation. When the asphalt contentis less than 8% by Weight the product mately 50% loses its Water resistantqualities.

I also prefer that at least 50% of the linal v product shall be bers and that the final product shall contain at least 9% by Weight of leather fibers. When the product contains less than 9% by weight of leather the ply adhesion is poor so that the layers of stock from which it ls made tend to separate from each other in particles of the board tend to break away in the trimming operation which tends to prevent the desirable final smooth nish for the visible edges of the heel base inthe completed heel.

leatherboard chips are 2.17% clay, approximately A suitable procedure for making a board containing talc as a ller is-as follows:

940 pounds of paper beaten in the beater, 215 pounds of talc are then added to the beater, and 59 pounds of the s aid -sodium silicate solution and 520 pounds of the saidasphalt dispersion are successively added and mixed; then 44 pounds of alum are added and mixed with the other ingredients. The stockis then passed over l the wet machine in the regular manner, and the dry product contains approximately 56.82% pa.- per ber, approximately 12.34% leather ber, approximately 14.21% asphalt, approximately 12.51% talc, and approximately 1.94%l aluminum silicate.

In manufacturing this disclosed herein, lthe asphalt becomes uniformly distributed in and among the bers-of the stock and remains so distributed in the nal product.

The product, containing not more than,20% a'sphalt and not less than 8% asphalt, is very water resistant, but upon sprinkling with water at spaced intervals of time it ywill/.absorb enough water to somewhat soften the product, and this property is of considerable importance, as hereinafter explained.

ber board useful in the manufacture of heel bases comprising 8 to 20% by weight of bitumi nous pitch type base and more than 50% by weight of brous material comprising cellulosic and leather bers. said fibrous material comprising atleast one-half cellulosic bers and less than one-half leather bers. 'said leather bers being ber and -249 pounds of felted sheet productas the trimming knives by weight of the ber board. and said bituminous pitch type basebeing uniformly distributed throughoutv the board', said berboard being relatively non-plastic and being characterized by a reticular fibrous structure.

v2. A water-laid felted Water-resistant sheet ber board useful in the manufacture of heel bases at least 9% `comprising 8 to 20% by,weight of asphalt base and more than 5,0% by weight of fibrous mate- .rial comprising cellulosic and leather bers, said brous material comprising at least lone-hall? cellulosic bers and less than one-half leather bers, said leather bers being at least 9% by weight of the ber board, and said asphalt base being uniformly distributed throughout the board, said berboard being relatively non-plastic and being characterized by a reticular brous structure.

3.A Water-laid felted water-resistant sheet ber board useful in the manufacture of heel bases consisting of from 63% to 92% by weight of brous material, from 8% to 20% by weight of bituminous pitch type base and the balance ller, said ller being no more than 17% by weight of the ber board, said brous material comprising cellulosic the leather bers consisting of less than one-half by weight of the total bercontent and at least 9% by weight of nous pitch type base being uniformly distributed throughout the board, said berboard being rel.

atively non-plastic and being characterized by a reticular brous structure.

4. A water-laid feitedwater-resistant sheet l bers and leather bers, the 'leather bers con-- sisting of less than one-half by weight of the total ber content vand at least 9% by weight of the ber board, and saidasphalt base being unformly distributed throughout the board, said berboard being relatively non-plastic and being characterized by a reticular brous'structure.

'HERMAN W. RICHTER.

bers and leather bers,

the ber board, and said bitumi- 

